* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    text-decoration: none;
}

html, body {
    height: 100%;
    background-color: #0060ff;
}

header {
    height: 6rem;
    background-color: #42c7ff;
}

.container {
    display: flex;
    height: calc(100% - 6rem);
    background-color: #b3ffe0;
}

.left-nav {
    width: 12rem;
    height: 100%;
    padding-top: 2rem;
    background-color: #343333;
}

.left-nav li {
    position: relative;
}

.left-nav a {
    position: relative;
    display: block;
    padding: .5rem 1rem .5rem 2.75rem;
    color: #ddd;
}

.left-nav a ~ ul {
    /*目前css3还没有合适的办法实现从固定高度到auto的过渡，
    原因跟计算模式有关，具体等后续版本来解决。本例采用jquery动画实现菜单下拉效果*/
    display: none;
}

.left-nav li.show>a ~ ul {
    display: block;
}

.left-nav a:before,
.left-nav a:after {
    content: "";
    position: absolute;
    width: .875em;
    height: .875em;
    background-size: contain;
}

.left-nav a:before {
    left: 1.25em;
    top: 55%;
    width: 1.125em;
    height: 1.125em;
    transform: translateY(-50%);
    background: url(../imgs/i_logo.png) no-repeat;
    background-size: contain;
}

.left-nav li.hasChild > a:after {
    top: .9375em;
    right: 1em;
    border: .125em solid #fff;
    transform: rotate(45deg) scale(.75);
    border-right: none;
    border-bottom: none;
    transition: all 150ms;
}

.left-nav li.show > a:after {
    top: .5rem;
    transform: rotate(225deg) scale(.75);
}

.left-nav li:not(.hasChild).active > a,
.left-nav li:not(.hasChild):hover > a {
    transition: all 200ms;
    background-color: rgba(67, 151, 247, 0.3);
}
.left-nav li:not(.hasChild).active > a {
    background-color: rgba(67, 151, 247, 0.7);
}

/*        .left-nav li:not(.hasChild).active > a,
        .left-nav li:not(.hasChild):hover > a {
            transition: all 200ms;
            background-color: #4397f7;
        }
        .left-nav li:not(.hasChild):hover > a {
            background-color: rgba(67, 151, 247, 0.7);
        }*/

/*一级菜单*/
.left-nav .menu1 {
    font-size: .9375rem;
    font-weight: bold;
}

/*二级菜单*/
.left-nav .menu2 {
    padding-left: 3.75rem;
    font-size: .875rem;
}

.left-nav .menu2:before {
    left: 2.25rem;
}

/*三级菜单*/
.left-nav .menu3 {
    padding-left: 4.75rem;
    font-size: .8125rem;
}

.left-nav .menu3:before {
    left: 3.25rem;
}




.main{
    flex: 1;
    font-size: 2em;
    background-color: #0060ff;
}
.test{
    padding: .5rem 1rem .5rem 2.5rem;
    font-size: .75em;
    background-color: #ff0098;
}